Was this mean of me?

I'm not sure if it's mean or not, but it's probably not the best way to handle the situation. It's better to redirect and if attacked, sternly say "NO!" and hiss as a mom cat would. They will outgrow it, but you must be consistent and redirect them to a more appropriate toy.

I don't think I would go so far as to say that your action was mean. In my opinion, to be mean requires you to be ill-intentioned. And, I don't think you wanted to cause Freddie harm. But, I would say that your action was not the best course to take and would suggest reading up on better ways to handle behavioral issues with kittens and cats. And, from this point on, I would not use the Tabasco sauce again. If you continued on with it, I would consider that to be mean or ill-intentioned. We do the best we can, but when we learn better, we do better. And, the simple fact that you came here asking for advice is proof that you do want to do what's best for Freddie. Kudos to you for that.

I agree with what Stephanie said. The best way to handle such behavior in a kitten is to redirect. When my older kitten goes into that old, aggressive (not mean, but play aggressive) behavior, I remove myself from the situation, tell him a stern no, and redirect him to one of his toys. And, 9 times out of 10, the redirection is enough to curb the behavior. It's something that I need to do continuously with even my adult cats, but it's a responsible and effective way to teach them what is acceptable and unacceptable behavior. It can be frustrating at times and it's certainly time consuming, but it is a way to go about teaching boundaries that positively reinforces your relationship with your kitty as opposed to having your cat fear or turn aggressive to you. Consistency is key, though. And, Freddie will test you. But, if you stay firm, he will learn the appropriate way to play with you.

Another option, and one that certainly requires more thought, is that, perhaps, you could adopt a second kitten to keep Freddie company and teach him appropriate and inappropriate behaviors. Of course, this would not mean that you would no longer have problems or need to work with your kitten (and, in this case, it would be two kittens), but it is something to consider since cats do learn from one another. I'm not advocating that you get a second cat, but I do want to point out that having more than one kitten often is beneficial -- especially when your kitten was abandoned and then adopted at such a young age (if I'm remembering correctly, Freddie was quite young when he came to the shelter and then to you).

Regardless, good luck. I know it's difficult to know how to go about handling certain situations. And, while I don't agree with using Tabasco sauce as a training aid, I can appreciate that you realized that your action was not necessarily best for Freddie and that you came here to ask for help so that you don't stray from teaching your kitten life skills in a healthy manner -- for both you and him. Please let us know how things progress and, always remember that we're here to help.

Do you have any wand toys such as daBird, the Cat Dancer or a fleece string on a wand? Also, an old soda can that's been cleaned and filled with a layer of dried beans and taped closed can be used as a rattle to get the kitty's attention to redirect.

Be sure to introduce them properly with the wait period, etc.
I don't think what you did was cruel. They make a spray to keep pets from chewing inappropriate places, I never thought about applying that spray to a human though.
Does this kitten like a laser light? I think he would love the toy Da Bird.

You have gotten great advice... I would only say if you need a taste deterent try something like bitter apple( safer for all than something that can literally de gunk a car battery)